Recreational Cyclocross and GravelbikingThis has to be the most physically intense sport ever invented. It's high speed bicycle racing on a short off road course or riding the off pavement rides on gravel like :The Dirty Kanza". We also have a dedicated Racing forum for the Cyclocross Hard Core Racers.

An inch sounds fine to me. As Andy K said, top tube length is the key metric. FWIW, I have shortish legs and a long torso and with the fatter tires and higher BB, the clearance on my CX is much tighter than my road bike but it matters not at all when riding.

Besides, if you miss the saddle on a flying remount, it's not going to matter if the top tube is 1 inch or 5 inches below. You're still going to smash nads.

It was said that the top tube is more important that the stand-over, why is this exactly? I have been riding a 52, 54 and 56 Jake the Snake and have found that both the 52 and 54 felt way too compact front to rear; it felt like when I was on the flats of the bars I was holding my knees. I know I could get a longer stem and setback post but that doesnt seem natural.

Additionally I felt, even with all the spacers under the stem that both the 52 and 54 were too low in the front. My logic sent me to the 56 but I have a tad less than an inch of stand-over clearance. It has not proved to be an issue for me but I hear that with racing it can be. Regardless, I bought a 56 JTS because it felt right and im sort of fishing for some confirmation that I am not a moron. Can someone clear up some CX geometry/fitment questions for me?

I do cross on a bike that is just a bit tall (top tube is fine) - for racing it's fine. Actually, when I missed the saddle once going downhill, I was able to ride the TT a bit while regaining the pedals - would have been harder if the TT was lower.

Where it's a pain is just riding around with the kids and stopping all over the place. I can't really chill out on the bike unless I fully dismount because the cables are right there under my bidness.

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“Courage is going from failure to failure without losing enthusiasm." (Churchill)

With Fuji Cross Comp geometry I would go one size smaller than what you think you are. I got my bike in 56cm which is the same as my road bike size and I wish I would have bought the 54cm. It's not that the size is way off but I think the 56cm is a tiny bit too big.

This bike measuring stuff is not consistent, compare the geometry tables. For example, the Masi CX bike in a 56 is very much like the Surly in a 54. In fact, if Masi were to measure the Surly, they would call a Surly a 56 and vice versa, Surly would call the Masi 56 a 54, lol. Don't hang on frame "sizes" but look at the geometry charts.

With Fuji Cross Comp geometry I would go one size smaller than what you think you are. I got my bike in 56cm which is the same as my road bike size and I wish I would have bought the 54cm. It's not that the size is way off but I think the 56cm is a tiny bit too big.

Too big in what respect?

If the OP had a specific road bike whose sizing he wanted to match, he could simply compare dimensions between the two. Which is what you should have done when getting your cross bike. The most relevant dimension is top tube (horizontal/theoretical), but if you really want to get fancy take a look at seat tube angle and headtube length, keeping in mind that cross forks are longer than road forks.

If the OP had a specific road bike whose sizing he wanted to match, he could simply compare dimensions between the two. Which is what you should have done when getting your cross bike. The most relevant dimension is top tube (horizontal/theoretical), but if you really want to get fancy take a look at seat tube angle and headtube length, keeping in mind that cross forks are longer than road forks.

I have long legs but very short torso so while I have a long saddle height, I have to use a small stem (90mm). This configuration works in the hoods but I don't feel super comfortable in the drops. Honestly I am in between a 54 and 56 which is a pain because both sizes can fit me but have to be adjusted differently to compensate. I have gone to two different fitters and really has not helped much.

What baffles me though is that I rode a Cervelo S3 which has way more aggressive geometry than my bike and I was insanely comfortable on both the drops and hoods. In fact the drops felt a lot more natural than the hoods. I have though about getting some new drop bars with a short reach like the 3T Ergonova to see if that solves the problem.

I have long legs but very short torso so while I have a long saddle height, I have to use a small stem (90mm). This configuration works in the hoods but I don't feel super comfortable in the drops. Honestly I am in between a 54 and 56 which is a pain because both sizes can fit me but have to be adjusted differently to compensate. I have gone to two different fitters and really has not helped much.

What baffles me though is that I rode a Cervelo S3 which has way more aggressive geometry than my bike and I was insanely comfortable on both the drops and hoods. In fact the drops felt a lot more natural than the hoods. I have though about getting some new drop bars with a short reach like the 3T Ergonova to see if that solves the problem.

I think that the more agressive geometry of the S3 fits your body better. Steeper ST angle shortens the toptube reach and put your hips closer to the bars. I had the opposite issue when I got my Soloist Team (now called the S1. I think the geometry is the same. Because I have short legs and a long torso, I needed a 120mm stem to not feel scrunched up.

I think that the more agressive geometry of the S3 fits your body better. Steeper ST angle shortens the toptube reach and put your hips closer to the bars. I had the opposite issue when I got my Soloist Team (now called the S1. I think the geometry is the same. Because I have short legs and a long torso, I needed a 120mm stem to not feel scrunched up.

Hmm I did not think about that. For my next bike I was going to go with a relaxed geometry CF frame but now I will have to look into the more aggressive ones like the Cervelo S2, Cannondale SuperSix, Fuji SST, etc.